Front Differential whine

[Whipple1]

Hope everyone is doing fine,I have a Quick question for people who have or had a front diffential whine or whirring sound at around 40+ mph.Its getting more noticable,I think I had it for a while now its just getting worse.Did anyone have this problem ?Is there some different oil or addative I can use to absorb the noise?If anyone had this fix done,what would be a good price.I would appreciate the feedback.Thanks.

 

[brodg]

i have rebuilt many front diffs. the problem with the gm diffs is the locking tabs break that hold the side bearing adjuster in place.and the backlash goes out of spec and then you get a whine either on or off of the accellerator. so you have to dissasseble the diff and replace the side carrier bearings and new adjusters and new locks. i get 800.00 labor plus parts.

 

[Whipple1]

Thanks for the info,Was wondering if the whole unit has to be removed from the truck? because there is no cover looks like it has to get split.I had my rear rebuilt because of excessive endplay and the guy rebuilt it with an Eaton posi has been flawless since.I have to see if they have a similiar unit for the front,I guess the Damn supercharger is stressing the drivetrain,I still have no regrets though lol.Thanks again for the info?

 

[boostaholic]

This is common on these trucks especially the silverado ss. The issue may be resolved early on by switching to a better gear oil (schaeffers, royal purple, amsoil, etc) but at this point you probably need a rebuild. My shop charges around $1500 for front and rear ring and pinions with new bearings and installation, I'm certain you could find a qualified shop to replace the front with good stuff for $1000 tops. I would invest in some yukon, precision, or dana spicer gears and it might be a good time to regear to 3.90s or 4.10s if you have ever contemplated doing so. The ifs 8.25 axles are notoriously weak and always break the bearing adjuster as previously stated. Once the backlash has gone and you lose your pattern the only solution is all new gears or you will hear the whine until the ring gear fails or something else. I can't recall what limited slips are available for those axles but I'll try to check at work tomorrow. I want to say detroit makes a tru-trac that works quite well but I'll have to make sure. What trans kit are you running? Check out finish line transmissions if you need a rebuild, I'm doing their level 5 on my 4l60 once I get one of those cool whooshy things in my exhaust :Chevy:

 

[Whipple1]

Thanks for the feedback,I have the blower for over 4 years now and have no complaints,My tranny was done by FB transmissions he basically just firmed the shift points so second gear wouldnt slip at WOT.The place I had my rear done is called Farks Supercars,I will be giving him a call to see what the damage will be for the front diff,just asking around to see what some of the members paid.As far as larger gears goes I stayed stock due to some highway driving I do,I would love to see what its like with 410s but with the fuel prices these days it would hurt:crazy: Let me know what kind of posi units are available,I have an Eaton posi for the rear.Thanks